Lots of little changes here (but the experiment configuration for the
paper experiments is preserved)... now all the hadoop setup scripts and
config files that are baked into the hadoop VM image are stored here in
the source tree, and then are also placed in the overall capnet ext
tarball that osp-capnet.py references.  Thus, no need for all the extra
and conf tarballs.  Now we only download hadoop and a wordfile (for
reproducibility of input) from www.emulab.net when we create the hadoop
image.

The hadoop config files included here are the ones that we need and are
working.  During image creation, they get baked into a tarball in the
image, and then extracted at VM runtime once the hadoop install scripts
have unpacked the hadoop tarball.  We wait til runtime to unpack hadoop
because it's huge.  But the conf dir we use is in the unpacked dir,
hence the need to wait to unpack our overlay conf tarball.

The hadoop config files here are slightly different than Unni's (but of
course they are the ones we used for the paper); there
are changes so that the slaves can contact the tracker on the master (I
think that's what it was); and more imporantly JVM and hadoop memory
limit adjustments to make the wordcount case work for our experiments.
I don't know how well they'll work for others... I might have
inadvertently required that VMs have 4096MB of memory minimum :(.  But
that is ok for us.

(Not sure about this... but it seems to be a good thing to do...)

All recv() are polling right now... hopefully this is a good set of
timestamps.

:) :) :)

This is a bit weird.  The user wfa receives node and passes them to the
membrane until it hasn't received any for 60 seconds; then it starts
trying to receive capabilities from the membrane; that is how it figures
out that Hadoop has finished.  The hadoop wfa doesn't send any caps back
until it has finished setting up; then it sends all flow caps it created
back to the user wfa.

Also some Hadoop utility scripts, and wrappers to run jobs we care about
for testing or whatever.

These don't have the password login Unni had done in expect.  Right now
we don't need that.  If we need that, we can add it as the "frontend"
script and then use these for the rest.

The other part of these scripts is the part that bakes the hadoop image,
in ../setup-capnet-basic.sh .

This is a bit odd, because the hadoop service wfa does not know when
it's done receiving node caps from the user/tenant wfa, and it has no
way to signal the user when it's done setting up.  Oh well.

(later on we have to fixup the pre-baked key stuff, of course)